1. Field of the Invention
The present invention relates generally to the field of capacitive fluid level detection for determining a volume of fluid in a container, such as a container used in a fluid dispensing system.
2. Description of Related Art
In various industries, fluid level sensors are used to determine the amount of fluid remaining in a container. For example, fluid level sensors have historically been utilized to indicate the level of fuel in a vehicle or the amount of beverage left in a carafe. Moreover, when employed in an automated mechanism, fluid level sensors may be used to determine when to perform a particular automated action.
Known fluid level sensors include capacitive fluid level sensors, which rely on the different dielectric properties of air and fluids in order to detect the presence or absence of fluid at a particular location within a container. For example, existing capacitive fluid level sensors include electrodes configured to apply an electric field at a plurality of locations along the height of a container. By measuring the capacitance at each of the plurality of vertical locations, the sensor can determine the fluid level within the container based on the differences among the measured capacitances.
However, such known fluid level capacitive sensors have installation requirements that make them impractical in many applications. For example, many capacitive fluid level sensors must have at least one electrode placed within the measured fluid itself in order to obtain accurate fluid level readings. Inserting a capacitor with exposed electrodes directly into a fluid may be difficult, or even dangerous, for volatile fluids within an enclosed container. Moreover, if access to the interior of the container is inhibited or prevented, it may be difficult or impossible to insert these sensors into the container.
In addition, many fluid level sensors require that at least one electrode be coupled to the exterior surface of the fluid container (e.g., immediately adjacent to the exterior surface of the fluid container). However, requiring sensors to be coupled to the external surface of the fluid container can be challenging where the sensors are used with removable fluid containers that are frequently installed or removed from a fluid dispensing machine, fluid containers positioned in difficult-to-access locations, and the like. As a result, there is often design complication, cost increase, and degraded user experience associated with apparatuses using such sensors. Therefore, a need exists for an improved fluid level sensor that may obtain accurate fluid level measurements and is capable of being more conveniently positioned relative to the fluid container being measured.